Uncaught (in promise) DOMException

[leolux]

The browser complains about the first line of the file service-worker.js:
Uncaught (in promise) DOMException

The first line contains this:
importScripts("/app/precache-manifest.i8462e3ab5fb69d3bcf042a9f14ebcc9.js", "https://storage.googleapis.com/workbox-cdn/releases/3.6.3/workbox-sw.js");